JP5326313B2 - Thrombus capture catheter - Google Patents

Description

The present invention relates to a thrombus capture catheter.

  Conventionally, percutaneous angioplasty such as stents and POBA (Plain Old Ballon Atherectomy) has been performed in vascular stenosis such as coronary arteries, carotid arteries, and vein grafts. This operation is one of revascularization techniques that secures blood flow by placing a stent or expanding a balloon at a vascular stenosis, and has achieved the expected results.

  However, in the above method, although the stenosis is expanded, plaques (bulging lesions) or blood clots released during the operation flow to the peripheral side of the lesion, causing infarction, No-Reflow phenomenon, etc., and reperfusion is obtained. There may not be. And many complications caused by such blood clots are serious.

  For example, in unstable angina pectoris or acute myocardial infarction in which a thrombus is involved in the coronary artery, the thrombus may be pushed out by stent placement or balloon expansion, and the blood vessel on the peripheral side of the lesion may be blocked. As a result, sufficient oxygen and nutrients are not supplied to the myocardium, causing myocardial damage such as myocardial necrosis. Similarly, when a blood vessel supplying blood to the brain is clogged, so-called cerebral infarction is caused and the brain tissue is dead.

  In particular, the carotid artery tends to stenosis due to arteriosclerosis, and blood flow to the brain is insufficient, or cerebral infarction is likely to occur due to a thrombus generated in the stenosis. Symptoms of such cerebral infarction include paralysis, numbness, aphasia, consciousness disorder, etc.-Functions that have been lost are not expected to recover 100% even after rehabilitation. It has a big influence on. Further, since a large amount of thrombus is attached to the venous graft stenosis portion that has been degenerated, attention is required.

  Thus, since infarction caused by a thrombus causes serious complications, in percutaneous angioplasty, protection of the peripheral side of the lesion is required. From this point of view, the following thrombus capture catheter has already been proposed (for example, see Patent Document 1).

JP 2004-97807 A

  This thrombus capture catheter has a thrombus capture member delivery sheath, a thrombus capture member operation shaft, and a thrombus capture member. The shaft has flexibility, is inserted into the delivery sheath so as to be movable in the axial direction, and projects forward from the distal end of the sheath. The thrombus capturing member is provided at the distal end portion of the shaft, and is stored in the distal end portion of the delivery sheath, and the entire portion protrudes forward in the axial direction of the sheath by the operation of the shaft. And expands radially outward and contracts in the axial direction.

  This thrombus capture catheter is inserted into a blood vessel and its tip is guided to the target blood vessel stenosis. Conventionally, the thrombus capture catheter is guided to the target blood vessel stenosis. No means were provided. Therefore, it is not easy to guide the tip of the thrombus capture catheter to the target vascular stenosis, and it is difficult to guide the tip of the thrombus capture catheter to the target branched blood vessel, particularly at the branch of the blood vessel. .

An object of the present invention is to provide a thrombus capture catheter that can be easily guides the distal portion of the blood thrombus capturing catheter into the vascular stenosis purposes.

In order to achieve the above object, the thrombus capture catheter of the present invention is characterized by A. A thrombus capture member delivery sheath; A thrombus capturing member operation shaft that is flexible and is inserted into the thrombus capturing member delivery sheath so as to be movable in the axial direction and protrudes forward from the distal end portion of the sheath; It is provided at the distal end of the shaft, is stored in the distal end of the sheath, protrudes forward in the axial direction of the sheath by operation of the shaft, expands radially outward through elastic deformation, and in the axial direction The guide tip is fixed to the tip of the shaft, and the guide tip is a. A distal-end side configuration portion that constitutes the distal-end side of the guide tip, the distal end portion having a smaller diameter than the base portion; The base side of the guide tip is configured, the base side of the tip side component is smaller in diameter, and the base side component is stepped with respect to the tip side component. An insertion hole is formed through which a guide wire that is open on the side surface of the distal end and the proximal end and is inserted so as to be relatively movable is disposed outside the sheath for delivering the thrombus capturing member. When the base side component is inserted into the distal end portion of the sheath when stored in the sheath, the proximal end surface of the distal side component portion abuts on the distal end surface of the sheath, thereby closing the distal end opening of the sheath. is there.
In addition, the thrombus capturing member is a. A spindle-shaped wire member in which a plurality of wires are spirally wound, a distal end portion and a proximal end portion converge radially inward, and an intermediate portion expands radially outward; It may have a filter that has a hole and is fitted and fixed to a substantially half portion on the distal end side of the wire member.

According to the present invention, the distal end portion of the thrombus capture catheter can be easily guided to the target vascular stenosis portion, and in particular, the distal end portion of the thrombus capture catheter can be easily guided to the target branched blood vessel at the branch portion of the blood vessel. .
Further , since the distal end portion of the distal end side constituting portion that constitutes the distal end side of the guide tip is smaller in diameter than the base portion, the thrombus capture catheter is moved in the blood vessel, and the distal end portion is guided to the target vascular stenosis portion. At this time, the movement resistance that the thrombus capturing catheter receives from the blood can be reduced.
Further , when the thrombus capturing member is stored in the sheath for delivering the thrombus capturing member, the proximal end surface of the distal end side configuration portion of the guide tip comes into contact with the distal end surface of the sheath, and the guide tip is excessively drawn into the sheath. Therefore, the guide wire inserted through the guide tip is not likely to be caught in the sheath. Further, when the thrombus capturing member is stored in the thrombus capturing member delivery sheath, moved in the blood vessel, and the distal end portion thereof is guided to the target blood vessel stenosis portion, the thrombus capturing member is stored in the sheath. However, at the time of storage, the distal end opening of the sheath is closed by the distal end side constituent portion of the guide tip, so that blood hardly penetrates into the sheath at the time of the movement.

  Hereinafter, a first example of an embodiment of the present invention will be described with reference to FIGS. 1 to 5. The thrombus capture catheter includes a thrombus capture member delivery sheath 1, a thrombus capture member operation shaft 2, and a thrombus capture. A member 3 and a guide tip 4 are provided.

  The sheath 1 is a flexible tubular body, and a lumen 6 that opens at the distal end is formed in the inside of the sheath 1 over the entire length (substantially) from the proximal end to the distal end. Since the sheath 1 needs flexibility and biocompatibility, it is made of a synthetic resin such as polyurethane, polyethylene, polyester, polypropylene, polyamide, polytetrafluoroethylene, and vinylidene fluoride.

  The shaft 2 operates the thrombus capturing member 3 and is a linear member having flexibility and flexibility. The shaft 2 is inserted into the lumen 6 of the sheath 1 so as to be movable (advanced and retracted) in the axial direction. 1 protrudes forward and rearward in the axial direction. The shaft 2 is made of a metal material such as stainless steel or a nickel-titanium alloy. A guide wire used for percutaneous angioplasty may be used as the shaft 2.

  The thrombus capturing member 3 is provided at the distal end portion of the shaft 2 and captures a thrombus, plaque or the like. The entire thrombus capturing member 3 is stored in the distal end portion of the sheath 1. The whole protrudes forward in the direction, and when this protrudes, the thrombus capturing member 3 expands outward in the radial direction and contracts in the axial direction through elastic deformation. Although the outer diameter of the thrombus capturing member 3 is not particularly limited, for example, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5 7.0, 7.5, and 8.0 mm, and it is preferable to select the outer diameter according to the vascular inner diameter of the lesioned part, that is, the vascular stenosis part. The thrombus capturing member 3 includes a wire member 8, a slide ring 9, a fixing ring 10, and a filter 11.

  The wire member 8 has a substantially spindle shape in which a plurality of wires 13 are spirally wound, the distal end and the proximal end converge radially inward, and the intermediate portion swells radially outward. As a forming material of the wire 13, a shape memory alloy can be adopted, and in general, a Ni—Ti alloy, a CuZn—Al alloy, or the like is adopted. When a shape memory alloy is employed as a material for forming the wire 13, the wire member 8 is usually stored in a shape (restored shape, original shape) as shown in FIG. When the thrombus capturing member 3 is applied to a lesion having many thrombuses, the wire member 8 may be formed longer so that more thrombuses can be captured. The number of the wires 13 constituting the wire member 8 is 8 to 16, preferably 8 to 14, and most preferably 8 to 12.

  The slide ring 9 is externally fitted to the distal end portion of the shaft 2 so as to be slidable (slidable) in the axial direction, and the distal end of the wire member 8 is fixed to the slide ring 9. The fixing ring 10 is externally fitted and fixed to the base side of the slide ring 9 at the distal end portion of the shaft 2, and the base end of the wire member 8 is fixed. These rings 9 and 10 are made of a metal material such as stainless steel.

  The filter 11 is a biocompatible material, for example, a non-woven fabric or a woven or knitted fabric made of a synthetic resin such as polyurethane, polyethylene, polyester, polypropylene, polyamide, polytetrafluoroethylene, or polyvinylidene fluoride. The bulging portion 15 on the base side and the converging portion 16 on the distal end portion side, and a plurality of holes 17 of a size that allows thrombus or the like to be captured but allows bodily fluids to pass through the transition portion of the bulging portion 15 to the converging portion 16. Is provided. The filter 11 is covered with approximately half of the distal end side including the swelled intermediate portion of the wire member 8 (except for a portion fixed by the slide ring 9 of the wire member 8), and the distal end of the converging portion 16 is the slide ring 9. And at least the bulging portion 15 is bound and fixed to the wire member 8 with a thread or the like. Note that the filter 11 may be dipped into the restored shape of the wire member 8, and then the hole 17 may be formed to cover the wire member 8. The diameter of the hole 17 is 50 μm to 1000 μm, preferably 50 μm to 500 μm, and most preferably 100 μm to 200 μm. If the diameter of the hole 17 is less than 50 μm, blood flow is hindered, and if it exceeds 1000 μm, the significance of providing the filter 11 is lost. When the thrombus is large, the thrombus capturing member 3 is not provided with the filter 11, and the thrombus capturing member 3 is constituted by the wire member 8, the slide ring 9 and the fixing ring 10, and the thrombus is formed by the stitch of the wire member 8. May be captured.

  The guide tip 4 has flexibility, is fixed to the tip of the shaft 2, and a guide wire 19 is inserted so as to be relatively movable, and guides the thrombus capture catheter by a cooperative action with the guide wire 19. The cross section is circular, and the tip side component 20 on the tip side and the base side component 21 on the base side are integrally formed. In the illustrated example, the shaft 2 does not protrude from the tip of the guide tip 4, but the shaft 2 may protrude from the tip of the guide tip 4. The distal-side component 20 constitutes the distal end side of the guide chip 4 and is connected to the base-side component 21 in the axial direction, and both have the same axial center. The diameter decreases toward the tip. The proximal end of the distal-side component 20 and the outer diameter of the sheath 1 are (substantially) the same, and when the thrombus capturing member 3 is stored in the sheath 1, the proximal end surface of the distal-side component 20 is the distal surface of the sheath. The distal end opening of the sheath 1 is closed by the distal end side configuration portion 20. As described above, when the thrombus capturing member 3 is stored in the sheath 1, the proximal end surface of the distal-side component 20 abuts against the distal end surface of the sheath, and the guide tip 4 is excessively drawn into the sheath 1. Therefore, the guide wire 19 inserted through the guide tip 4 is not likely to be caught in the sheath 1. The distal end side configuration portion 20 is formed with an insertion hole 22 that opens at the side surfaces of the distal end and the proximal end portion and through which the guide wire 19 is inserted. The insertion hole 22 is inclined with respect to the axial center and is curved with respect to the axial center. The base side component 21 constitutes the base side of the guide tip 4, has a smaller diameter than the base end of the tip side component 20, is stepped with respect to the tip side component 20, and has a truncated cone shape. It is made to become a small diameter as it goes to a base end. The base-side component 21 has a smaller diameter than the inner diameter of the sheath 1, that is, the diameter of the lumen 6, and when the thrombus capturing member 3 is stored in the sheath 1, the base-side component 21 is the distal end of the sheath 1. Inserted in the department. Since the guide tip 4 needs flexibility and biocompatibility, it is made of the same material as the sheath 1. The maximum outer diameter of the guide chip 4 is 0.8 to 2 mm. The inner diameter of the insertion hole 22 is 0.4 to 1.2 mm.

  Next, percutaneous angioplasty for removing thrombus and plaque from the vascular stenosis using the thrombus capture catheter of the present invention will be described. First, the guide wire 19 is inserted into the blood vessel 24 in advance, and the distal end portion of the guide wire 19 is passed through the blood vessel stenosis portion 25 of the target blood vessel 24 as shown in FIG.

  Next, the proximal end portion of the guide wire 19 is inserted into the insertion hole 22 of the guide tip 4 of the thrombus capture catheter, the thrombus capture catheter is inserted into the blood vessel 24, and the guide wire 19 is guided while the guide tip 4 is guided. As shown in FIG. 4, the guide wire 19 is slid along the guide wire 19 and guided to the target blood vessel 24 by the guide action of the guide wire 19 and the guide tip 4 in cooperation. Then, the blood vessel 24 is allowed to pass through the blood vessel constriction portion 25.

  In this way, the guide action by the cooperative action of the guide wire 19 and the guide tip 4 can guide the thrombus capture catheter to the target blood vessel 24, so that the distal end portion of the thrombus capture catheter can be easily formed into the target blood vessel stenosis section 25. In particular, the thrombus capture catheter can be easily guided to the intended branched blood vessel, particularly at the branch of the blood vessel.

  Further, when the thrombus capturing member 3 is stored in the sheath 1, the distal-side component portion 20 outside the sheath 1 in the guide tip 4 is configured to have a smaller diameter toward the distal end. When the thrombus capture catheter is moved in the blood vessel, the movement resistance that the thrombus capture catheter receives from the blood can be reduced.

  Furthermore, when the thrombus capturing member 3 is stored in the sheath 1, the proximal end surface of the distal-side component 20 contacts the distal surface of the sheath 1, and the distal opening of the sheath 1 is blocked by the distal-side component 20. Therefore, when moving the thrombus capture catheter through the blood vessel, blood hardly or hardly enters the sheath 1.

  After passing the distal end portion of the thrombus capture catheter through the vascular stenosis portion 25 of the blood vessel 24 as described above, the sheath 1 is placed in the axial direction rear side (front side, proximal side) with the shaft 2 fixed. 5), as shown in FIG. 5, the entire thrombus capturing member 3 protrudes outward from the sheath 1, expands (expands) radially outward via elastic deformation, and contracts in the axial direction. , Close contact with the inner wall of the blood vessel 24.

  Next, the shaft 2 and the thrombus capturing member 3 are left in the blood vessel 24, and only the sheath 1 is removed from the patient's body, and a separately prepared balloon catheter (not shown) is externally fitted to the shaft 2 and the balloon (not shown) (Not shown) is inserted up to the vascular stenosis part 25 and expanded with a pressure medium, and the adhering material 27 such as thrombus and plaque is released from the vascular stenosis part 25 and is captured by the thrombus capturing member 3. Thereafter, the pressure medium is discharged from the balloon, the balloon is deflated, and only the balloon catheter is removed from the body.

  Thereafter, a sheath for recovering a thrombus capturing member (not shown) having a diameter larger than that of the delivery sheath 1 is externally fitted to the shaft 2 and the distal end thereof is inserted to the front of the blood vessel stenosis 25, and then the shaft 2 is fixed. In this state, the recovery sheath is pushed forward in the axial direction (the tip side of the shaft 2). As a result, the base side of the thrombus capturing member 3 comes into contact with the distal end of the recovery sheath, and the thrombus capturing member 3 contracts radially inward and elastically deforms, and expands in the axial direction. 3, that is, the base side of the wire member 8 and the base end portion of the bulging portion 15 of the filter 11 are accommodated in the distal end portion of the recovery sheath.

  In this way, only the base side of the thrombus capturing member 3, that is, the base side of the wire member 8 and the base end portion of the bulging portion 15 of the filter 11 are accommodated in the distal end portion of the recovery sheath. There is no possibility that thrombus or the like housed in the thrombus capturing member 3 leaks from the hole 17 of the filter 11 without being excessively compressed.

  As described above, after the base side of the thrombus capturing member 3 is housed in the distal end portion of the recovery sheath, the recovery sheath is removed from the body together with the shaft 2 and the thrombus capturing member 3, so that the percutaneous angioplasty 24 is performed. Is completed.

  6 and 7 show examples of the second example and the third example of the embodiment of the present invention, respectively, and the guide tip 4 has a substantially spindle shape (substantially rugby ball shape) or the same. It has a similar shape, and its maximum outer diameter portion is disposed at a substantially central portion or tip end side in the axial direction of the guide tip. If the maximum outer diameter portion of the guide tip 4 is larger than the inner diameter of the thrombus capture member delivery sheath 1, the maximum outer diameter portion is the sheath 1 when the thrombus capture member 3 is stored in the sheath 1. By being in contact with the distal end of the sheath 1, excessive pulling of the guide tip 4 into the sheath 1 can be prevented and the distal end opening of the sheath 1 can be closed.

  In the second and third examples of the embodiment of the present invention, if the maximum outer diameter portion of the guide tip 4 is smaller than the inner diameter of the thrombus capturing member delivery sheath 1, the thrombus capturing member 3 There is a possibility that the guide tip 4 is excessively drawn into the sheath 1 when stored in the sheath 1. What solved this is the fourth example and the fifth example of the embodiment of the present invention shown in each of FIGS.

  In the fourth example of the embodiment of the present invention shown in FIGS. 8 and 9, a bottomed cylindrical blocking member 31 that closes the proximal end opening is externally attached to the proximal end of the thrombus capturing member delivery sheath 1. The shaft 2 is inserted through the closing member 31 after being fitted and fixed. The closing member 31 is made of a synthetic resin such as polypropylene, ABS resin, polyvinyl chloride, polyethylene, or polyethylene terephthalate, or a metal material such as stainless steel or brass. A side injection tube 32 is connected to the closing member 31 so that heparin or the like for preventing blood coagulation can be injected into the sheath 1. A hemostatic valve 33 is inserted into the proximal end portion of the closing member 31 to prevent blood leakage from the insertion portion of the shaft 2 in the closing member 31. A contact portion 34 made of a ring-shaped elastic material is fitted on the base portion of the shaft 2. The contact portion 34 is not movable in the axial direction with respect to the shaft 2, but the contact portion 34 is formed with a slit 38 extending from the outer surface to the inner surface over the entire length in the axial direction. Due to the elastic deformation of the portion 34, the shaft 2 can be detached from the contact portion 34 through the slit 38. A stopper 35 is fixed to the base end surface of the closing member 31 and is continuously provided in the axial direction. The stopper 35 has a cylindrical shape in which both sides in the axial direction are closed, and the base portion of the shaft 2 is movably inserted in and removed from the axial direction, and the contact portion 34 is moved in the axial direction. It is freely decorated. The proximal end portion of the stopper 35 is a rear movement restriction 36 that abuts the abutment portion 34 and restricts the movement of the shaft 2 in the axial direction rearward, and the distal end portion of the stopper 35 abuts on the abutment portion. It is set as the front movement control part 37 which controls the movement to the axial direction front of a shaft.

  According to the above configuration example, when the thrombus capturing member 3 is stored in the sheath 1, the axial center of the shaft 2 is obtained by the cooperative action of the abutting portion 34 provided on the shaft 2 and the backward movement restriction 36 of the stopper 35. The backward movement of the guide tip 4 can be restricted, and the guide tip 4 can be prevented from being excessively drawn into the sheath 1, so that there is no possibility of the guide wire 19 inserted through the guide tip 4 being caught in the sheath 1. it can. Further, when the sheath 1 is pulled rearward in the axial direction (near side, proximal side) and the thrombus capturing member 3 protrudes from the sheath 1 to the outside, the forward movement restriction 37 of the contact portion 34 and the stopper 35 is reduced. By the cooperative action, the movement of the shaft 2 forward in the axial direction can be restricted, and the separation distance from the distal end of the sheath 1 of the thrombus capturing member 3 can be easily set to an appropriate distance. Further, when the delivery sheath 1 is replaced with a thrombus capturing member recovery sheath, the sheath 1 and the stopper 35 can be easily removed from the shaft 2 by detaching the shaft 2 from the contact portion 34 through the slit 38. Can be removed.

  In the fifth example of the embodiment of the present invention shown in FIG. 10, a side hole 39 through which the shaft 2 can be inserted is formed in the side wall of the distal end portion of the sheath 1, and the partition wall 40 is formed in the distal end portion of the sheath 1. The partition wall 40 is formed so that the inside of the partition wall 40 communicates with the side hole 39 and the distal end side of the shaft 2, and the shaft 2 is inserted through the inside.

It is a longitudinal cross-sectional view which shows the 1st example of embodiment of this invention. It is a side view which shows the state which the thrombus capture member of FIG. 1 expanded. It is a longitudinal cross-sectional view which shows the use condition of FIG. It is a longitudinal cross-sectional view which shows the use condition of FIG. It is a longitudinal cross-sectional view which shows the use condition of FIG. It is a longitudinal cross-sectional view which shows the 2nd example of embodiment of this invention. It is a side view which shows the 3rd example of embodiment of this invention. It is a longitudinal cross-sectional view which shows the 4th example of embodiment of this invention. It is AA arrow sectional drawing of FIG. It is a longitudinal cross-sectional view which shows the 5th example of embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Thrombus capture member delivery sheath 2 Thrombus capture member operation shaft 3 Thrombus capture member 4 Guide tip 8 Wire member 11 Filter 13 Wire 17 Hole 19 Guide wire 20 Tip side component 21 Base side component 22 Insertion hole 34 Contact portion 35 Stopper 36 Backward movement restriction 37 Forward movement restriction part

Claims (2)

A. A thrombus capture member delivery sheath;
B. A thrombus capture member operating shaft that is flexible and is inserted into the thrombus capture member delivery sheath so as to be movable in the axial direction and protrudes forward from the distal end of the sheath;
C. It is provided at the distal end of the shaft, stored in the distal end of the sheath, protrudes forward in the axial direction of the sheath by operating the shaft, expands radially outward via elastic deformation, and axially A thrombus capture member that shrinks to
A guide tip is fixed to the tip of the shaft,
Guide tip
A. A tip-side component that constitutes the tip side of the guide tip, the tip part having a smaller diameter than the base part; and
B. The base side of the guide tip is configured, the base side of the tip side component is smaller in diameter, and the base side component is stepped with respect to the tip side component.
An insertion hole is formed in the distal-side component part, and a guide wire that is opened on the side surface of the distal end and the proximal end part and is inserted so as to be relatively movable is disposed outside the sheath for delivering the thrombus capturing member .
When the thrombus capturing member is stored in the thrombus capturing member delivery sheath, the base side component is inserted into the distal end portion of the sheath, and the proximal end surface of the distal side component is in contact with the distal end surface of the sheath, A thrombus capture catheter that occludes the distal opening of the sheath. The thrombus capture member
A. A spindle-shaped wire member in which a plurality of wires are spirally wound, and a distal end portion and a proximal end portion converge radially inward and a middle portion swells radially outward;
B. Has a hole, thrombus capture catheter of claim 1 further comprising a filter which is fitted to a substantially half portion of the front end portion of the wire member fixed.

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